1774: The Continental Congress approves a resolution prohibiting slave importations and further American participation in the slave trade.

1775: Lord Dunmore, Virginia's royal governor, promises freedom to any slaves who desert rebellious masters and serve in the Crown's forces.

1777: Vermont's Constitution outlaws slavery.

1779: John Laurens proposes to Congress the arming of 3,000 slaves to resist a British invasion of the South; Congress approves the proposal but the South Carolina legislature rejects it.

1780: Pennsylvania adopts a gradual emancipation law.

1782: A Virginia law permits private manumissions.

1784: By a single vote, Congress rejects Jefferson's proposal to exclude slavery from the western territories after 1800.

1787: The Constitutional Convention agrees to count three-fifths of a state's slave population in apportioning representations; forbids Congress from ending the Atlantic slave trade until 1808; and requires fugitive slaves to be returned to their owners.

1787: The Northwest Ordinance prohibits slavery north of the Ohio River and east of the Mississippi.

1790: The Quakers and the Pennsylvania Abolition Society petition Congress to discourage the slave trade and slaveholding producing an uproar in Congress.

January 1, 1831: Garrison begins publishing The Liberator, the country's first publication to demand an immediate end to slavery. On the front page of the first issue he declares: "I will not equivocate--I will not excuse--I will not retreat a single inch--AND I WILL BE HEARD." Georgia offers $5000 to anyone who would bring him to the state for trial.

August 22, 1831: Nat Turner leads a Southampton County, Virginia.

Christmas 1831: A slave insurrection erupts in Jamaica.

1833: The British Parliament adopts a gradual emancipation plan providing compensation to slave owners and establishing an apprenticeship plan to prepare nearly 800,000 slaves for freedom.

December, 1833: Garrison and some 60 other delegates, male and female and black and white, form the American Anti-Slavery Society in Philadelphia.

1831: Lane theological seminary in Cincinnati expels antislavery students, including Theodore Weld, many of whom become agents for the American Anti-Slavery Society.

1839: 39 African captives led by Joseph Cinque rebel against their Cuban captors and order two surviving whites to sail the Amistad to Africa. The ship is seized off the coast of Long Island and the Africans are jailed in Connecticut.

1840: The American Anti-Slavery Society splits over women's right to participate in the administration of the organization and the advisability of nominating abolitionists as independent political candidates.

1840: James Birney, the Liberty Party presidential candidate, receives fewer than 7100 votes.

1841: The Supreme Court frees the Amistad captives on the grounds that the international slave trade is illegal.

1844: Liberty Party presidential candidate receives 62,000 votes, capturing enough votes in Michigan and New York to deprive Whig candidate Henry Clay of the presidency.

1844: Congress narrowly approves the annexation of Texas.

1846: The United States declares war with Mexico.

1846: The House of Representatives adopts the Wilmot Proviso, which would bar slavery from any territory acquired from Mexico. The Senate rejects the proviso.

1848: Under the Treaty of Guadalupe Hidalgo, the United States acquires one-third of Mexican territory.

1848: Conscience Whigs and antislavery Democrats merge with the Liberty Party to form the Free-Soil Party, which demands the abolition of slavery in the District of Columbia and exclusion of slavery from the federal territories. Presidential nominee Martin Van Buren receives 300,000 votes (about 10 percent of all votes cast).

1850: The Fugitive Slave Law, part of the Compromise of 1850, strips accused runaways of the rights of trial by jury and of testifying in their own defense.

1851: A gun battle erupts in Christiana, Pa. between abolitionists and slave catchers.

1854: The Republican party is organized following passage of the Kansas-Nebraska Act, which opens Kansas and Nebraska territories to white settlement and repeals the Missouri Compromise line restricting slavery in the northern part of the Louisiana Purchase.

1854: Garrison publicly burns a copy of the U.S. Constitution, calling it "a covenant with death and an agreement with Hell."

May 24, 1856: John Brown and six companions murder five pro-slavery men and boys at Pottawatomie Creek, Ks., part of a war of revenge that leaves 200 dead.

January, 1857: NM Supreme Court invalidates practice of using law enforcement to enforce peonage and debt bondage in Mexican community, in case of Jaramillo v. Romero

October 16, 1859: John Brown leads a raid on the federal arsenal at Harpers Ferry, Va.

March 2, 1865: passage of Peonage statute ("an act to prohibit certain forms of peonage in New Mexico Territory" made it clear that 13th amdt guarantees wasn't just for African Americans.

July 20, 1997: Justice Department arrests 18 people and dismantles ring which held 56 deaf and hearing-impaired Mexicans in involuntary servitude and forced them to peddle trinkets in New York and Chigago.

October 28, 2000: Trafficking Victims Protection Act of 2000 creates expanded federal anti-slavery laws to reach psychological coercion and provides special immigration provisions so alien victims of modern-day slavery can remain safely in the United States.